Abstract
The direct numerical simulations (DNSs) of the turbulent Ekman layer over a smooth flat surface are performed. The Reynolds numbers are set to be Re_f=400 and 600,where Re_f is defined by Re_f=G/√<vf/2> with use of the geostrophic wind velocity G, kinematic viscosity v and Coriolis parameter f. The turbulent structure in Ekman layer shows the three-dimensional nature. A large-scale structure appears in the high upper region where the geostrophic balance is observed. In this region, the inertial oscillation can be obtained even in the turbulent field. In addition, the effect of Reynolds number onto the three-dimensional characteristics of the turbulent structure is examined. The effect of the large-scale structure onto the passive scalar transport is also discussed.
